Times that the prospect of Singapore hosting a leg was "very promising".

If it was to be held here, the race would take place between April and June next year, he had said then.

However, in response to a my paper query this week, he said: "Other events taking place in Singapore in 2010 - including the Youth Olympic Games - and construction on the Marina Bay Sands integrated resort contributed to us not being able to stage a race (here)."

The Marina Bay area was the proposed venue for the race.

Criteria for a host city include a spectacular backdrop, a large enough area for the 6km aerial track over water or land, and about 500,000 spectators.

When contacted, a Singapore Tourism Board (STB) spokesman said: "Discussions for an event of this scale and stature are complex, although we recognise that it has the potential to enhance Singapore's profile as an attractive destination."

It is not known how much the air race would have raked in for Singapore.

Singapore's F1 race last year, with an estimated budget of up to $150 million, drew more than 40,000 overseas visitors and generated nearly $168 million in tourist receipts.

Other cities that have hosted the race have benefited from the tourist dollars brought in. Canada's Ontario, for example, reportedly invested more than $3 million to host a leg in June this year, and estimated economic dividends of around $100 million.

Industry insiders here had earlier told my paper that the air race might not happen, because of concerns over whether the economy could support a calendar packed with events like the US$75-million ($105-million)